Classical realist theories, a cornerstone of international relations scholarship, fundamentally understand the international system through the lens of power and self-interest. At the heart of this perspective lies a specific conception of "national interest," which is not merely an abstract notion but a tangible, driving force behind state actions. For classical realists like Hans Morgenthau and E.H. Carr, national interest is primarily defined in terms of power – the ability of a state to influence the behavior of others. This essay will argue that classical realism posits national interest as a multifaceted concept, rooted in the fundamental human drive for security and a desire for more power, which consequently shapes state policy towards self-preservation, expansion, and the pursuit of relative gains in a perpetually anarchic international environment.
Hans Morgenthau, arguably the most influential classical realist, articulated national interest as the primary determinant of foreign policy in his seminal work Politics Among Nations (1948). He posited that states, like individuals, are driven by a "lust for power," and their actions are best understood as attempts to acquire and maintain it. This power, for Morgenthau, is not an end in itself but a means to an end: security. The international system, characterized by anarchy – the absence of a supreme global authority – compels states to prioritize their own survival. Therefore, national interest is inextricably linked to ensuring the state's existence and territorial integrity. This leads to a foreign policy aimed at securing these vital interests, often through a pragmatic assessment of the balance of power. For instance, the historical alignment of nations during the Cold War, where states coalesced around the United States or the Soviet Union, can be seen as a manifestation of this principle, as each bloc sought to enhance its security and power relative to the opposing bloc.
E.H. Carr, in The Twenty Years' Crisis (1939), also emphasized the centrality of interest, though he critiqued the idealistic notion of universal interests. For Carr, what states perceive as their "national interest" is often a rationalization of their desires, imbued with a sense of moral righteousness. However, he too recognized that in an anarchic world, states will pursue their perceived interests, which inevitably involve a struggle for power. This pursuit is not necessarily driven by malice but by a rational calculation of self-preservation in an environment where cooperation is unreliable and trust is scarce. The historical pursuit of colonial territories by European powers in the 19th century, for example, was often framed as a national interest—securing resources, markets, and strategic advantage—even if it came at the expense of other populations. This illustrates how national interest, as understood by classical realists, can drive expansionist policies in the pursuit of relative gains, even when absolute gains for all might be possible.
The concept of national interest in classical realism is also informed by a pessimistic view of human nature. Morgenthau believed that the political behavior of nations reflects the inherent flaws of human nature, including egoism and the desire for dominance. This philosophical underpinning suggests that the pursuit of power and the struggle for national interest are not temporary aberrations but enduring features of the human condition, projected onto the international stage. Consequently, international politics is seen as a continuous competition, a struggle for survival and influence. The actions of states, therefore, are less about achieving a utopian peace and more about managing the inherent conflict arising from competing national interests. The constant arms races observed throughout history, from the pre-World War I naval buildup to the nuclear standoff during the Cold War, exemplify this relentless pursuit of security through increased military power, a direct consequence of perceived national interest.
In conclusion, classical realist theories firmly anchor their understanding of international relations in the concept of national interest, defined primarily as the pursuit of power for the sake of security. This perspective, rooted in a belief in self-interested human nature and the anarchic nature of the international system, posits that states act to preserve themselves and enhance their relative power. Whether through pragmatic alliances, strategic military buildup, or territorial expansion, the enduring drive to secure and advance national interests remains the central organizing principle of foreign policy according to this influential school of thought. The historical record, replete with examples of states acting to protect and expand their influence, provides consistent, if sometimes stark, validation for this enduring realist framework.